ESC 301.01 The Environmental Dimension PDF

ESc 301.01 The Environmental Dimension I-INTRODUCTION Ferhan Çeçen  What is the Environment? The environment encompasses the whole of life on earth and the complex interactions that link the living world with the physical world. In a general sense, this covers everyt...

ESc 301.01 The Environmental Dimension I-INTRODUCTION Ferhan Çeçen  What is the Environment? The environment encompasses the whole of life on earth and the complex interactions that link the living world with the physical world. In a general sense, this covers everything contained within the air, land and water. A collection of all the Earth’s ecosystems: -biosphere -hydrosphere -atmosphere -lithosphere  A Little Environmental History Before 1960, few people had ever heard the word ecology, and the word environment meant little as a political or social issue. Then came the publication of Rachel Carson’s landmark book, Silent Spring (Boston: Houghton Mifflin, 1962). It is a classic book on problems associated with toxins in the environment. At about the same time, several major environmental events occurred, such as oil spills along the coasts of Massachusetts and southern California, and highly publicized threats of extinction of many species, including whales, elephants, and songbirds. The environment became a popular issue.  Elements of the Scientific Method Science A body of knowledge (facts and explanations) about the natural world and the process used to get that knowledge. Scientists collect evidence (observations) and use this evidence to draw conclusions (inferences) in an effort to understand the natural world. Elements of the Scientific Method Elements of the Scientific Method  Environmental Science Environmental science is the study of the interactions among the physical, chemical and biological components of the environment. It focuses on pollution and degradation of the environment related to human activity; and the impact on biodiversity and sustainability. Environmental science attempts to explain ❖ how life on the Earth is sustained, ❖ what leads to environmental problems, ❖ how these problems can be solved. Many sciences are important to environmental science. These include: biology (especially ecology, that part of biology that deals with the relationships among living things and their environment), geology, hydrology, climatology, meteorology, oceanography, soil science etc. Also engineering sciences are required to deal with most of environmental problems. Environmental science includes also other fields that have to do with how we value the environment, from environmental philosophy to environmental economics. Environmental Science  Environmental Science The goals of environmental science are to learn: how nature works. how the environment affects us. how we affect the environment. how we deal with environmental problems how we can live more sustainably without degrading our life-support system. We have made significant progress in many areas of environmental science (although our scientific understanding of the environment still lags behind our need to know). We have also begun to create legal frameworks for managing the environment, thus providing a new basis for addressing environmental issues. Thinking like a scientist  Approaches to environmental science Human population growth The global population has risen dramatically during the last century. Underlying nearly all environmental problems is this rapid rise in human population. The Black Death, also known as the Great Plague, the Black Plague, or the Plague, resulted in the deaths of an estimated 75 to 200 million people from 1347 to 1351.  Approaches to environmental science Sustainability Sustainability means that a resource is used in such a way that it continues to be available. Some would define it as follows: we have the right to use the Earth’s resources and Earth capital to meet our needs, but we have the obligation to pass on the Earth’s resources and services to future generations in as good or better shape than these conditions were passed on to us. Sustainability  Approaches to environmental science Resources Nonrenewable resource: A resource that forms at a rate that is much slower than the rate at which it is consumed Renewable resource: A natural resource that can be replaced at the same rate at which the resource is consumed. It can be replenished with the passage of time, either through biological reproduction or other naturally recurring processes. Potentially renewable resource: This resource can be replenished fairly rapidly through natural processes. They can be depleted if used beyond sustainable yield.  Earth’s Carrying Capacity It is difficult to determine Earth’s carrying capacity. Estimates of Earth’s carrying capacity for people range from 2.5 to 40 billion, but about 15 billion is the upper limit with today’s technology. The differences in capacity have to do with the quality of life projected for people—the poorer the quality of life, the more people can be packed onto the Earth.  A global perspective We now know that human activities can affect the environment globally. Recognition that civilization can change the environment at a global level is relatively recent. For example, as we discuss in detail in later parts, scientists now believe that emissions of modern chemicals are changing the ozone layer high in the atmosphere. Critical thinking issue: What is more important: the quality of your local environment or the quality of the global environment—the environment of the entire planet? Environmental problems are global  An urban world In part because of the rapid growth of the human population and in part because of changes in technology, we are becoming an urban species, and our effects on the environment are more and more the effects of urban life. Cities and towns get larger. Agricultural lands and coastal wetlands are lost. Species loose their habitats. As urban areas expand, wetlands are filled in, forests cut down, and soils covered over with pavement and buildings.  Values and the Environment Deciding what to do about an environmental problem involves both values and science. Many people see the earth as a resource to be mined rather than as a trust to be cared for. We must choose what we want the environment to be. But to make this choice, we must first know what is possible. That requires knowing the scientific data and understanding its implications. Three common worldviews  Case Study: Birds at Mono Lake: Applying science to solve an environmental problem This case study highlights the problems of Mono Lake in California where over a million birds use a lake that is drying up and becoming salty due to the diversion of water to the city of Los Angeles. The questions posed to a panel of scientists studying the lake were 1) without stream input how small would the lake become and 2) would it become too salty to support aquatic life and when? The answers were yes, too salty by 2003. What to do was a question of values, water for Los Angeles or water for the lake. In the end, the courts sided with the lake.  Placing a Value on the Environment The value of the environment is based on five justifications: The utilitarian justification is that some aspect of the environment is valuable because it benefits individuals economically or is directly necessary to human survival. For example, conserving lions in Africa as part of tourism provides a livelihood for local people. The ecological justification is that an ecosystem is necessary for the survival of some species of interest to us, or that the system itself provides some benefit. Aesthetic and recreational justifications have to do with our appreciation of the beauty of nature and our desire to get out and enjoy it. For example, many people find wilderness scenery beautiful and would rather live in a world with wilderness than without it. One way we enjoy nature’s beauty is to seek recreation in the outdoors.  Placing a Value on the Environment Moral justification has to do with the belief that various aspects of the environment have a right to exist and that it is our moral obligation to help them, or at least allow them, to persist. Cultural justification refers to the fact that different cultures have many of the same values but also some different values with respect to the environment. This may also be in terms of specifics of a particular value. All cultures may value nature, but, depending on their religious beliefs, may value it in different degrees of intensity. Analysis of environmental values is the focus of a new discipline, known as environmental ethics.  UNDERLYING CAUSES OF ENVIRONMENTAL PROBLEMS Major environmental and resource problems  Environmental Pollution Pollution is the harmful alteration of our environment by our own actions. Pollutants – either unwanted by-products or our activities or the obnoxious residues of things we have made, used, and thrown away. Pollutants can have three types of unwanted effects: Can disrupt / degrade life-support systems. Can damage health and property. Can create nuisances such as noise and unpleasant smells, tastes, and sights. Three factors determine how severe the harmful effects of a pollutant are: The concentration level: ppm, ppt etc. Chemical nature: how active and harmful it is in nature? Half-life or the persistence of the pollutant. (DDT is an example of a persistent pollutant).  Types of Pollution Air pollution – Most air pollution is caused by the burning of fossil fuels. Water pollution – Sewage – Eutrophication – Infectious agents – Organic chemicals – Inorganic and miscellaneous chemicals – Sediments from land corrosion – Radioactive substances – Waste heat from power plants and industry Pharmaceuticals and personal care products (PPCPs): Many different substances are being used in medicines such as painkillers, antibiotics, contraceptives, beta-blockers, lipid regulators etc. The world’s people consume enormous quantities of skin care products, dental care products, soaps, sunscreen agents, and hair styling products—to name just a few.  Types of Pollution (Continued) Land pollution – Pesticides – chemicals used to kill insects defined as pests. – Herbicides – chemicals used to kill plant life, particularly weeds. – Chemical wastes – Radioactive fallout – Acid rain – Garbage Global warming – Since the late 1800’s the average global surface temperature has increased about 0.75 degrees C. – Most warming has occurred since 1950.  Solutions to Pollution Pollution Control Pollution Prevention